Structure of composites obtained with Al-Al2O3-Al3Fe-Al3Ti composite powders
Józef Śleziona, Maciej Dyzia, Jerzy Myalski, Jakub Wieczorek Politechnika Śląska, Katedra Technologii Stopów Metali i Kompozytów, ul. Krasińskiego 8, 40-019 Katowice
Annals 4 No. 10, 2004 pages 170-174
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abstract In this work the results of investigation concern to the examination of composite structures with complex phase composition Al2O3-Al3Fe-Al3Ti have been presented. The composite powders have been manufactured in controlled reaction process between ilmenite powders and liquid aluminum at temperature above 720oC. The obtained powders have been selected and reduced their size in ball mill. Results of particle analysis of powders have been presented at Table 1, and phase composition in Figure 1. Powders of 45÷80 and 80÷120 μm have been used to production of composite samples. Composites have been made by two methods: cold compaction (300 MPa) and sintering (800oC/1 h), hot pressing at Degussa press. The different parameters of compaction have been used. Structure of composites obtained by cold compaction and sintering shows Figure 3. Figure 4 shows structure of that same composite but obtained after hot pressing at 800oC/15 MPa/15 min. The best compaction parameters of composite powders are: hot pressing in vacuum at 1000oC/10 MPa/15 min, but composite powders must be early consolidated at 800oC/15 MPa and heated at 1100oC. Phase composition of composite obtained according to that procedure (XRD analysis) has been shown in Figure 2. Structure of that composite shows Figure 5. It has been confirmed that elaborated technique used to the manufactured of composite led to obtain of composite reinforced with intermetallic Al-Fe-Ti system with the hardness above 1000 HV. Key words: composite powders, intermetallic phases, cold compaction, hot pressing, structure of composite